Number of days available for climatic review
| Parameter | Jan | Feb | Mar | Apr | May | Jun |
| Tmax | 521 | 474 | 525 | 519 | 552 | 534 |
| Tmin | 522 | 472 | 526 | 522 | 555 | 535 |
| Duration of sunshine | 303 | 249 | 337 | 332 | 390 | 320 |
| Precipitation | 529 | 480 | 530 | 528 | 562 | 544 |
| Humidity/Visibility | 88 | 80 | 89 | 100 | 119 | 117 |
| Parameter | Jul | Aug | Sep | Oct | Nov | Dec |
| Tmax | 554 | 529 | 509 | 524 | 508 | 520 |
| Tmin | 551 | 528 | 510 | 527 | 509 | 520 |
| Duration of sunshine | 394 | 307 | 328 | 337 | 263 | 234 |
| Precipitation | 561 | 559 | 539 | 556 | 542 | 127 |
| Humidity/Visibility | 121 | 121 | 116 | 115 | 111 | 118 |
Climate data is usually derived from meteorological data of a certain number of years. The actual number of recorded years may vary from only a couple to 50 years or more. The quality of climate data depends on the number of available recorded years. Fewer years means less reliable data. The standart-period for reliable climate data is 30 years. For example, the mean monthly temperature for, let's say January, would ideally calculated from a total number of 930 recorded January-days. However, the usual number of recorded days is much smaller. The table above shows the actual number of recorded days for every parameter measured. |
